The present invention relates to an automatic lubrication apparatus for hydraulic tools associated with heavy machinery, particularly heavy machinery used for construction and excavation.
The present invention relates to an automatic lubrication apparatus which is designed and intended to be mounted on a hydraulic tool that can be driven by a hydraulic-pressure medium and is in particular a detachable component of a construction machine, which is designed to be mounted on a hydraulic hammer of an excavator, such that the lubrication apparatus sends lubricant from a lubricant reservoir through a lubricant conduit to one or more sites to be lubricated, and comprises a lubricant pump including a pump element against which a cam cyclically impacts.
Automatic lubrication means for hydraulic tools associated with a construction machine are sufficiently well-known.
However, parts of such conventional lubrication means are disposed centrally in the construction machine, which is advantageous in that this position is less exposed to oscillation and is more protected, but presents the disadvantage that very long leads are needed, and more effort is required to exchange the hydraulic tool for another hydraulic tool, and to remove or attach the existing hydraulic tool.
Given this background, the document WO 02/33309 A1 has already proposed a lubrication apparatus designed and intended to be mounted on a hydraulic hammer that can be driven by a hydraulic-pressure medium and is a detachable component of an excavator, according to the structure described at the outset. This previously known apparatus, however, has the disadvantage that in this case the eccentric device that drives the pump element is driven by linear reciprocating movement of the free end of a selector piston that is part of a progressive distributor, with an intervening freewheel mechanism. The result is a relatively jerky movement of the eccentric, because only the movement of the selector piston in the direction to drive the eccentric forward can be used, whereas in the phase of retraction of the piston the eccentric comes to a halt. Even the forward movement of the selector piston is irregular.